The intent of this investigation is to investigate the possibility that by deliberately reducing organ functional work load with anesthetics, protection against major organ ischemia might be afforded. Because it has been reasonbly well demonstrated that barbiturates do indeed exert protection against partial cerebral ischemia in animals, we have concentrated our efforts on the myocardium. We have, thus far, tested the hypothesis that barbiturates might also exert specific protection against acute regional myocardial ischemia using a partial myocardial ischemia model in which we are able to measure myocardial oxygen consumption directly, we find that there is no evidence that barbiturates are, in fact, exerting myocardial protection and, in fact, some evidence that they may be harmful to ischemic myocardium. This is surprising and clinically relevant because of the currently widely touted practice of administering large doses of barbiturates to patients who have just undergone a cardiac arrest in order to "protect brain". If that cardiac arrest was, in fact, caused by myocardial regional ischemic disease, we feel that we have shown this practice to be deleterious to the myocardium. The direction of our future work will be to expand on this finding and test various other anesthetics with respect to their ability to preserve biochemically or improve the function of myocardial ischemic tissue. We have already tested halothane and enflurane and find them to be superior to pentobarbital in this regard. We intend to test large dose fentanyl, large dose morphine, and diazepam intravenous anesthetics using this same model. We believe that by studying the ischemic tissue biochemical quality, through the use of ATP, ADP, AMP and mitochondrial function determinations, we have circumvented the problem of quantifying infarct size and are instead looking at infarcting tissues quality. We are also engaged in numerous myocardial function studies, using angiographic wall motion studies, ventricular function curves, and hope in the future to obtain the use of the new Mayo Clinic dynamic spatial reconstructor, currently being developed by Drs. Earl Wood, Erik Ritman and associates at our Institution.